Overview of research projects

Project Details:
Surveys on the epidemiology or prevalence of helminth infections in wildlife will contribute to a better knowledge of parasite distribution and help implementing prevention strategies in terms of the One Health concept. Furthermore, the evaluation of new diagnostic tools will improve health monitoring in wildlife.

Results:

Bisterfeld, K., Raulf, M.-K., Waindok, P., Springer, A., Lang, J., Lierz, M., Siebert, U., Strube, C. (2022) Endoparasites of peritoneal organs and skeletal muscles of the European wildcat (Felis silvestris) in Germany. Parasite & Vectors 17, 473

 

Schütte, K., Springer, A., Brandes, F., Reuschel, M., Fehr, M., Strube, C. (2024) Ectoparasites of European hedgehogs (Erinaceus europaeus) in Germany and their health impact. Parasites & Vectors 17, 2

 

Rehbein, S., Jůnková Vymyslická, P., Peterka, T., Strube, C., Visser, M., Mayr, S., Lackerschmid, J. (2024) Calicophoron daubneyi (Paramphistomidae) in deer of the ?umava National Park, Czech Republic - Consequence of prevalent rumen fluke infection in cattle. Veterinary Parasitology: Regional Studies and Reports 50, 101012

 

Bisterfeld, K., Raulf, M.-K., Waindok, P., Springer, A., Lang, J., Lierz, M., Siebert, U., Strube, C. (2022) Cardio-pulmonary parasites of the European wildcat (Felis silvestris) in Germany. Parasite & Vectors 15, 452

 

Waindok, P., Raue, K., Grilo, M., Siebert, U., Strube, C. (2021) Predators in northern Germany are reservoirs for parasites of One Health concern. Parasitology Research 120, 4229-4239

Project Details:
Gap junctions (Gj) are composed of two hemichannels called connexons, which are responsible for direct intercellular communication between adjoining cells. Each cell contains one connexon, composed of six connexin (cx) proteins. The so far discovered functions of Gj are mostly limited to the transport of molecules and ions (< 1 kDa). Nevertheless these junctions tend to be selective and specialize in cellular growth and differentiation (Bruzzone et al., 1996; Kumar and Gilula, 1996). As of today there are at least twenty different cx genes coding for Gj in humans and mice. One of the most researched Gj proteins is Cx43. In the testis, Cx43 is located between two Sertoli cells (SC) and between SC and germ cells (GC), it is involved in testicular development, GC and SC differentiation and spermatogenesis. SC nurture the developing GC and aid in their translocation and development from the basal to the adluminal compartment of the seminiferous tubule. Cx43 is further participating in blood-testis barrier formation and composition together with tight and adherens junctions as member of the "SC-SC junctional complexes" (Carrette et al., 2010).
A conditional SC-specific knockout (KO) of the Gja1 gene (SCCx43KO) revealed Cx43 expression in SC as an absolute requirement for normal testicular development and initiation of spermatogenesis (Brehm et al., 2007; Sridharan et al., 2007). Adult SCCx43KO mice showed normal testis descent, but testis size and weight was drastically lower when compared with heterozygous and WT littermates. Histological analysis revealed that SC specific deletion of Cx43 mostly results in an arrest of spermatogenesis at the level of spermatogonia or SC-only syndrome, intratubular cell clusters, abnormal SC cytoplasmic vacuoles, increased SC numbers and reduced number of spermatogonia per seminiferous tubule. Furthermore, as SCs were found to be still proliferating in adult mice (Sridharan et al., 2007), it was postulated that lack of Cx43 expression in SCs caused these somatic cells to remain in an apparently permanent proliferative state. These results emphasize the critical contribution of Cx43 to the normal maturational progression of SCs which normally results in the cessation of SC mitogenesis during the pubertal period.
Thus, as of today only one mouse stem with SCCx43KO-/- has been established in vivo (Brehm et al., 2007; Sridharan et al., 2007), yet no successful in vitro culturization of a &#61508;Cx43 SC line has been published. Although Carette et al. (2010) were successful in a partial inhibition of the Gj through siRNAs, a complete in vitro knockout may provide beneficial results in understanding the roles of Cx43 for normal spermatogenesis and may help to develop a mechanistic hypothesis in understanding the altered functions of Cx43 in SC leading to impaired spermatogenesis.

Funding: EU-Interreg, Bavarian Nordic, 270.000 EUR

Project Details:
Ticks transmit various human and animal pathogens. With regard to pathogens, the vector function of ticks for the causative agent of Lyme borreliosis (Borrelia burgdorferi sensu lato complex), human and animal granulocytic anaplasmosis and tick-borne encephalitis (TBE virus) is of particular importance. Studies on the abundance and distribution of ticks and their pathogens are therefore essential for assessing the One Health risk. Regarding tick-transmitted pathogens, this project collects data not only for Germany but also at the international level.

Results:

Rapp, J., Springer, A., Strube, C. (2024) Ixodes ricinus ticks survive flooding.  Ticks and Tick-Borne Diseases 15, 102417

 

Springer, A., Jordan, D., Höltershinken, M., Barutzki, D., Strube, C. (2024) Endemisation and management of Babesia divergens on a beef production farm. Current Research in Parasitology & Vector-Borne Diseases 6, 100188

 

Springer, A., Lindau, A., Probst, J., Fachet, K., Schäfer, I., Dobler, G., Mackenstedt, U., Strube, C. (2024) Germany-wide Citizen Science study reveals spread of Babesia canis-infected Dermacentor reticulatus ticks by dogs travelling within the country. Current Research in Parasitology & Vector-Borne Diseases 6, 100d187

 

Probst, J., Springer, A., Fingerle, V., Strube, C. (2024) Frequency of Anaplasma phagocytophilum, Borrelia spp. and coinfections in Ixodes ricinus ticks collected from dogs and cats in Germany. Parasites & Vectors 17, 87

 

Probst, J., Springer, A., Topp, A.-K., Bröker, M., Williams, H., Dautel, H., Kahl, O., Strube, C. (2023) Winter activity of questing ticks (Ixodes ricinus and Dermacentor reticulatus) in Germany − Evidence from quasi-natural tick plots, field studies and a tick submission study.  Ticks and Tick-Borne Diseases 14, 102225

Cooperation Partners:

Dr. O. Kahl, tick-radar GmbH

Prof. Dr. U. Mackenstedt, Universität Hohenheim

Dr. V. Fingerle, Nationales Referenzzentrum für Borrelien, Oberschleißheim

Prof. Dr. G. Dobler, Nationales Konsiliarlabor für FSME, München

Dr. L. Chitimia Dobler, Fraunhofer-Institut für Immunologie, Infektions- und Pandemieforschung

Project Details:
In diesem Projekt werden in einem transgenen Mausmodell die Folgen einer Sertoli Zell-spezifischen Deletion des Connexin43-Gens auf die Regulation der Spermatogenese u.a. mittels Microarray und qRT-PCR untersucht. Ausgewählte signifikant veränderte Kandidatengene aus den Mausversuchen werden zudem mit Hodenbiopsien von infertilen Männern verglichen.
Das Projekt bildet die Grundlage verschiedener Forschungsprojekte und Dissertationen sowie künftiger Drittmittelprojekte.
Geldgeber:
DFG, Klinische Forschergruppe KFO181, Male factor infertility due to impaired spermatogenesis
Volumen: 250000 ?

Results:

https://www.sciencedirect.com/science/article/pii/S1642431X17302371?via%3Dihub

Cooperation Partners:

Dr. Daniela Fietz, JLU Giessen

Klinische Forschergruppe Giessen + Marburg

http://www.uni-giessen.de/cms/fbz/fb11/forschung/forschergruppen/kfo_181/home

Project Details:
Ticks of the genus Ixodes transmit various human and animal pathogens. In this long-term project running since 2005, pathogen prevalence in ticks in the city of Hannover, Germany, is monitored to investigate potential effects of climate change. In addition to the infection status of the ticks, the tick density in the Hannover area will also be determined.

Results:

Glass, A., Springer, A., Raulf, M.-K., Fingerle, V. Strube, C. (2023) 15-year Borrelia prevalence and species distribution monitoring in Ixodes ricinus/inopinatus populations in the city of Hanover, Germany. Ticks and Tick-Borne Diseases 13, 102074

 

Glass, A., Springer, A., Strube, C. (2022) A 15-year monitoring of Rickettsiales (Anaplasma phagocytophilum and Rickettsia spp.) in questing ticks in the city of Hanover, Germany. Ticks and Tick-Borne Diseases 13, 101975

 

Hauck, D., Springer, A., Chitimia-Dobler, L., Strube, C. (2020) Two-year monitoring of tick abundance and influencing factors in an urban area (city of Hanover, Germany). Ticks and Tick-Borne Diseases 11, 101464

 

Blazejak, K., Raulf, M.-K., Janecek, E., Jordan, D., Fingerle, V., Strube, C. (2018) Shifts in Borrelia burgdorferi (s.l.) geno-species infections in Ixodes ricinus over a 10-year surveillance period in the city of Hanover (Germany) and Borrelia miyamotoi-specific Reverse Line Blot detection. Parasites & Vectors 11, 304

 

Blazejak, K., Janecek, E., Strube, C. (2017) A 10-year surveillance of Rickettsiales (Rickettsia spp. and Anaplasma phagocytophilum) in the city of Hanover, Germany, reveals Rickettsia spp. as emerging pathogens in ticks. Parasites & Vectors 10, 588

Cooperation Partners:

Dr. V. Fingerle, Nationales Referenzzentrum für Borrelien, Oberschleißheim

Project Details:
The project is aimed at the modelling and analysis of diverse veterinary epidemio-logic data arising from consultant work. The range of statistical modelling ap-proaches includes general models and special topics like logistic regression, zero inflation, non-linear regression (especially growth curves), cluster analysis, contin-gency table analysis and multi-block redundancy analysis (multi-factorial and multi-variate linear regression analysis).

Results:

Kreienbrock L, Pigeot I, Ahrens W.

Epidemiologische Methoden. Berlin: Springer Spektrum; 5. Auflage 2012.

ISBN: 978-3-8274-2333-7

 

Berke, O. Modified median polish kriging and its applica-tion to the Wolfcamp-Aquifer data.

Environmetrics. 2001;12(8):731-48.

 

Kreienbrock L, Broll S. Methodische Aspekte zur Qualitätssicherung veteri-närepidemiologischer Studien. [Methodologic aspects of quality assurance in veterinary epi-demiological studies].

Dtsch Tierarztl Wochenschr. 1999 Sep;106(9):381-5.

Cooperation Partners:

- Fachbereich Statistik, Universität Dortmund

- Leibniz-Institut für Epidemiologie, Bremen

- Hochschule Hannover

- Department of Population Medicine, University of Guelph

Project Details:
Ziel der Entwicklung von Leitlinien zur Guten Klinischen Praxis war die Gewährleistung international anerkannter ethischer und wissenschaftlicher Qualitätsanforderungen in zulassungsrelevanten Arzneimittelstudien. Da ein hoher Qualitätsstandard aber auch in anderen Bereichen wünschenswert ist, werden GCP Prinzipien zunehmend auch bei anderen Studien oder Untersuchungen angewandt.

Dieses Projekt verfolgt das Ziel, den Inhalt der Guideline dem betroffenen Personenkreis bekannt zu machen und darauf hinzuwirken, die Qualitätsanforderungen auch im Bereich der universitären Forschungsprojekte umzusetzen. Aus biometrischer Sicht wird dabei besonderes Gewicht auf die die Statistik und das Datenmanagement betreffenden Teile der Leitlinie gelegt.

Neben der Information werden dazu auch Dienstleistungen, etwa die Mitarbeit bei der Erstellung von Prüfplänen oder Review von Studienprotokollen angeboten. Insbesondere wird angestrebt, bei vom Institut betreuten und ausgewerteten Studien GCP-konform zu arbeiten und ggf. dazu notwendige "Standard Operating Procedures" (SOPs) zu erarbeiten.

Results:

Kreienbrock L, Pigeot I, Ahrens W. Epidemiologische Methoden. Berlin: Springer Spektrum; 5. Auflage 2012. ISBN: 978-3-8274-2333-7

 

Glaser S, Kreienbrock L. Stichprobenplanung bei veterinärmedizinischen Studien. Ein Leitfaden zur Bestimmung des Untersuchungsumfangs. Hannover: Schlüter-sche; 2011. ISBN-13: 978-389993-078-8 ISBN-10: 3-89993-078-9

 

Glaser S, Dahms S, Röhmel J, Weiß H, Kreienbrock L. Statistische Grundlagen von "Good Clinical Practice" in der Veterinärmedizin - ein Positionspapier zur Planung, Durchführung und Auswertung empirischer Untersuchungen. Dtsch Tierarztl Wo-chenschr. 2002 Feb;109(2):68-72.

Funding: Grimminger-Stiftung, 20.000 EUR

Project Details:
The hepatitis E virus (HEV) is mainly transmitted to humans through meat and meat products from infected animals. The transmission route via the environment through contaminated soil, water and/or (arable) plants has long been discussed. Possible vectors include manure or waste water. Many studies show that a considerable proportion of meat and sausage products as well as many wastewater and even surface water samples can be tested positive for HEV RNA. All these studies are based on RT-PCR testing, i.e. the detection of the HEV genome. In order to carry out a better risk assessment, for example when consuming food, and to be able to identify the spread of the virus and chains of infection more precisely, it is necessary to determine the intactness and thus the infectivity of the virus in such samples. In this project, meat and sausage samples as well as environmental samples in the form of manure and wastewater will be analyzed for the presence of HEV RNA as well as for the infectivity of the virus. For this purpose, a stable and efficient cell culture system has been established in recent years, which has already been successfully used to isolate HEV capable of replication from wild and domestic pig organ samples.

Funding: Ministerium für Energiewende, Klimaschutz, Umwelt und Natur (MEKUN), 23.177 EUR

Project Details:
Recently, there has been an increase in strandings of sea turtles on the Schleswig-Holstein coast. Between 2022 and 2024, a total of five animals have stranded so far. The loggerhead turtle, leatherback turtle and Atlantic bastard turtle were found.
The reasons for the current increased occurrence of sea turtles in the North Sea are not known. In general, the water temperatures here are too cold for the animals, especially in winter. As a result, the animals enter a state of rigidity, as reptiles are highly dependent on the ambient temperature. In this state, the animals can no longer move actively and drift with the current. The recent increase in the number of finds could indicate a new trend, but this will have to be confirmed over the next few years. However, due to the expected rise in temperature as a result of climate change, a more frequent occurrence of these sea creatures on our coasts seems likely in the long term.
The main aim of this pilot study is to collect data on the occurrence of sea turtles on the coasts of Schleswig-Holstein. Dead stranded sea turtles will be dissected at the Institute for Terrestrial and Aquatic Wildlife Research (ITAW) in order to uncover the causes of stranding and the incidence of disease.
The project is divided into the following five subsections.
1. data collection: Data on sea turtles stranded on the Schleswig-Holstein coast will be collected. To this end, contact is made with various stakeholders such as the LKN, the Wadden Sea Protection Station, the Jordsand e.V. association and local fishermen. The strandings that occur during the course of the project are also recorded.
2. genetic studies: Samples from dead and live stranded turtles will be genetically analyzed to determine the species and subpopulation.
3. dead body monitoring: Dead stranded sea turtles will be pathologically examined at the ITAW to obtain information on morphometrics, age, sex and disease incidence. In addition to recording biometric data, a macroscopic examination of the carcass is carried out. Depending on the state of preservation of the carcass and the presence of signs of disease, further examinations are carried out. These include histology, parasitology and microbiology.
4. participation in live strandings: The ITAW supports the country in the event of live strandings. This includes advice, contacting international experts, investigation and sampling.
5. establishment of international contacts: This project also aims to establish contacts with sea turtle experts in Europe and worldwide, firstly to become part of the global turtle network and secondly to be able to obtain expert advice on various topics.

Funding: Aarhus University, Danish Centre for Environment and Energy (DCE), 27.329 EUR

Project Details:
The aim of the project is to process the survey data from the summer period and aggregate the quality-checked data for the Belt-Sea-Region in the period 2005-2024; or a period close to that depending on data and model checking. An extraction of relevant environmental covariates, describing the habitat of harbour porpoises, and a fit of a species distribution model (generalized additive model GAM) is planned. The final selected model enables the spatial prediction of the harbour porpoise summer density in the study area. Subsequently, a model validation, estimation of the model error and confidence intervals is planned. Finally, a short technical report will be written to describe the method and the results with a focus on Danish Belt-Sea-Region.